1. Field of the Invention
The present invention relates to a leadless semiconductor device with a substrate chamfered for providing a connector. It also relates to a method of making such a semiconductor device.
2. Description of the Related Art
FIGS. 24 and 25 of the accompanying drawings show an example of conventional semiconductor device. The illustrated device includes a ceramic substrate 90, a semiconductor chip 91 mounted on the substrate, and a resin package 92 enclosing the chip 91. The chip 91 is provided with electrodes (not shown) which are directly or indirectly (i.e., via wires W) connected to pads 93 formed on the upper surface of the substrate 90. On its lower surface, the substrate 90 is formed with terminals 94 connected to the pads 93 via connection holes 8.
Referring to FIG. 26, the conventional device is fabricated in the following manner. First, a mother substrate 90A of unbaked inorganic material is prepared. Then, pads 93 are formed on the upper surface of the mother substrate 90A. The pads 93 include a number of pairs of one larger pad and two smaller pads. Though not shown in FIG. 26, a plurality of terminals (reference numeral 94 in FIG. 25) are formed on the lower surface of the mother substrate 90A. These terminals are connected to the larger and smaller pads 93 by connection holes 8 (shown in broken lines). Each connection hole 8 is produced by stuffing tungsten powder into a through-hole formed in the mother substrate 90A. Then, the mother substrate 90A is baked at a temperature of about 1200° C. Thereafter, semiconductor chips 91 are mounted on the larger ones of the pads 93 in electrical conduction therewith, and enclosed with resin material. Finally, the mother substrate 90A is cut along the predetermined lines N1, N2, thereby providing a plurality of semiconductors as shown in FIG. 24.
While the illustrated prior art is functional, it also has the following drawbacks.
First, since the substrate 90 needs to be formed with several connection holes 8, the downsizing of the substrate (hence the device as a whole) is rather difficult.
Second, the collective fabrication process (FIG. 26) of the prior art is time-consuming due to many connection holes 8 to be made in the mother substrate 90A.
Third, the inorganic mother substrate 90A tends to deform when it is subjected to baking. Disadvantageously, such deformation may cause positional deviation of the pads 93 or terminals 94.